Adjustable stinger bit for bulldozer blade

ABSTRACT

A stinger bit on a bulldozer blade which is retractable to a point where its cutting edge aligns with the cutting edges of bits on opposite sides of the stinger bit so that the bits combine to provide what is in effect a straight cutting edge on a conventional bulldozer and particularly, a support and adjusting means for such a bit which is simple and compact.

United States Patent Max D. Fryrear;

Eugene M. Wilson, Joliet, Ill.

Jan. 26, 1970 Feb. 2, 1971 Caterpillar Tractor Co.

Peoria, 111.

a corporation of California Continuation of application Ser. No. 708,566, Feb. 27, 1968, now abandoned.

Inventors Appl. No. Filed Patented Assignee ADJUSTABLE STINGER BIT FOR BULLDOZER BLADE 6 Claims, 3 Drawing Figs.

US. Cl 172/802, 172/664 Int. Cl E021 3/76, A01 b 65/06 'Field of Search 172/664,

[56] References Cited UNITED STATES PATENTS 2,899,760 8/1959 Armington et a1 172/777 2,993,285 7/1961 l-loxie 172/777 3,039,209 6/1962 Cron et al .1 37/98 3,238,648 3/1966 Cobb et al. 172/664 Primary ExaminerRobert E. Pulfrey Assistant ExaminerStephen C. Pellegrino Attorney-Fryer, Tjensvold, Feix, Phillips & Lempio ABSTRACT: A stinger bit on a bulldozer blade which is retractable to a point where its cutting edge aligns with the cutting edges of bits on opposite sides of the stinger bit so that the bits combine to provide what is in effect a straight cutting edge on a conventional bulldozer and particularly, a support and adjusting means for such a bit which is simple and compact.

PATENIED EB 2mm 315597-49 SHEET 1 [IF 2 INVENTORS MAX D. FRYREAR EUGENE M. WILSON BY w W W ATTORNEYS PATENTEUFEB 2|97| 7 3,559,74

' SHEETZUFZ INVENTORS MAX D. FRYREAR EUGENE M. WILSON WWMM, 2 *M' ATTORNEYS ADJUSTABLE STINGER BIT FOR BULLDOZER BLADE This is a continuation of application Ser. No. 708,566, filed Feb. 27, 1968 and now abandoned.

A bulldozer with an adjustable stinger bit is disclosed in our assignees US. Fat. to Cobb and l-leinold No. 3,238,648. Among the advantages of such a bit, as set forth in said patent, are that it reduces the power required for making a cut in hard ground and provides cutting ends close to the center of the blade for making pioneer cuts in a hillside or the like, thus reducing stresses on the blade.

A disadvantage of an adjustable stinger bit on the bulldozer is that it requires support and adjusting means directly behind the center portion of the blade where space is at a premium because of the desirability of having the blade as close as possible to the tractor.

It is the object of the present invention to provide an adjustable stinger bit for a bulldozer with a very simple, strong and compact support and adjusting means.

Further and more specific objects and advantages of the invention are made apparent in the following specification wherein reference is made to the accompanying drawings.

In the drawings:

FIG. 1 is a view in rear elevation of a bulldozer blade having a stinger bit and adjusting means therefore constructed in accordance with the present invention, the ends or wings of the blade being broken away;

FIG. 2 is a sectional view taken on line 22 of FIG. 1; and

FIG. 3 is a view like FIG. 2 but taken on line 33 of FIG. 1.

The bulldozer shown in the drawings has a curved blade or moldboard generally indicated at with the usual reinforcing structure behind it which need not be discussed in detail herein. It is carried by conventional push arms 11, see FIGS. 2 and 3, each of which extends rearwardly and is connected with a side of the tractor by a pivotal joint which enables raising and lowering of the moldboard. Wings at the end of the moldboard are partially illustrated in FIG. 1 but are not important to an understanding of the present invention. Instead of the conventional long hardened cutting edge at the lower portion of the moldboard, the present invention has two end bits or cutting edges shown at 14 in FIG. 1, one also being visible in FIG. 2, and a single centrally disposed stinger bit 15. The stinger bit 15 is adjustable from its fully raised position shown in FIG. 2, wherein it cuts through the earth on the same plane as the end bits 14 for accomplishing work like that of a conventional bulldozer to a lowered position shown in FIG. 3 and shown in broken lines in FIG. 1, wherein it is capable of cutting into the ground to a considerable depth while the end bits do not enter the ground. The stinger bit is secured to the forward face of a plate 16 which reinforces it and also extends above it so that when the bit is in its lowered position, as in FIG. 3, the upper portion of the plate 16 covers the opening in the moldboard which would normally be covered by the central portion of a full-length cutting edge in a conventional bulldozer. The stinger bit 15 and plate 16; are adjustable in a generally vertical direction by a pair of arms 18 which are slidably disposed in boxlike guides 19 and are secured at their ment of links 18. This causes the jacks 20 to operate in unison,

thus preventing cocking of the stinger bit support assembly; The jacks 20 are included in a conventional hydraulic circuit, not shown, controlled from the operators station of the tractor upon which the bulldozer is mounted.

As is apparent in FIGS. 2 and 3, extension of the jacks raises the stinger bit toward its uppermost position and it is lowered by contraction of the jacks. Because of the rectilinear movement of the arms 18 and stinger bit, it is possible to obtain all of the necessary motion of the bit with mechanism disposed very close to the back of the moldboard as distinguishe from the construction in the patent hereinabove referred to wherein the stinger bit is raised and lowered by swinging about a pivot disposed rearwardly of the moldboar We claim:

1. In a bulldozer having a blade normally positioned on ground level to substantially lie in a vertically disposed plane, first and second transversely spaced cutting edges secured on opposite ends of a lower, forward edge of the blade and disposed in a cutting plane defining an acute angle relative to said vertically disposed plane, a third cutting edge movable linearly between an upper position in at least substantial alignment with said first and second cutting edges and a lower position vertically therebelow, support means attached to said third cutting edge, guide means secured to said blade for guiding movements of said support means and third cutting edge to continuously maintain said third cutting edge at least substantially in said cutting plane and coplanar with respect to said first and second cutting edges during movements thereof between said upper and lower positions, and actuating means mounted on said blade and attached to said support means to selectively move said third cutting edge between said upper and lower positions.

2. The invention of claim 1 wherein said support means comprises elongated and laterally spaced arms attached to said third cutting edge.

3. The invention of claim 2 wherein said guide means comprises a boxlike guide reciprocally mounting each one of said arms therein.

4. The invention of claim 1 wherein said actuating means comprises hydraulic jack means.

5. The invention of claim 2 wherein said actuating means comprises a hydraulic jack means attached to each one of said support means and connections between said jack means and said arms including pivoted levers.

6. The invention of claim 5 further comprising means connecting said levers together to compel them to move in unison.

26 with the upper ends of the arms 18. The bell- 

1. In a bulldozer having a blade normally positioned on ground level to substantially lie in a vertically disposed plane, first and second transversely spaced cutting edges secured on opposite ends of a lower, forward edge of the blade and disposed in a cutting plane defining an acute angle relative to said vertically disposed plane, a third cutting edge movable linearly between an upper position in at least substantial alignment with said first and second cutting edges and a lower position vertically therebelow, support means attached to said third cutting edge, guide means secured to said blade for guiding movements of said support means and third cutting edge to continuously maintain said third cutting edge at least substantially in said cutting plane and coplanar with respect to said first and second cutting edges during movements thereof between said upper and lower positions, and actuating means mounted on said blade and attached to said support means to selectively move said third cutting edge between said upper and lower positions.
 2. The invention of claim 1 wherein said support means comprises elongated and laterally spaced arms attached to said third cutting edge.
 3. The invention of claim 2 wherein said guide means comprises a boxlike guide reciprocally mounting each one of said arms therein.
 4. The invention of claim 1 wherein said actuating means comprises hydraulic jack means.
 5. The invention of claim 2 wherein said actuating means comprises a hydraulic jack means attached to each one of said support means and connections between said jack means and said arms including pivoted levers.
 6. The invention of claim 5 further comprising means connecting said levers together to compel them to move in unison. 